Shoring structure



July 18, 1967 E. WENNINGER 3,331,210

SHORING STRUCTURE Filed Aug. 24, 1964 INVENTOR.

ROBERT E. WENNIINGER BY RONALD E. BARRY United States Patent 3,331,210 I SHORING STRUCTURE Robert E. Wenniuger, 3810 Lakeside Road, Pewaukee, Wis. 53072 Filed Aug. 24, 1964, Ser. No. 391,637 1 Claim. (Cl. 6141) This invention relates to sheathing or shoring devices and, more particularly to an improved sheathing structrue that is used to prevent cave ins in trenches of the type dug for pipelines or the like.

Most states today have enacted codes setting forth the sheathing or shoring requirements for digging trenches to protect the workmen. These codes generally specify certain plank sizes and cross-brace sizes, with their distance apart under different soil and depth conditions. Due to the limited life of wood and the variations in trench widths encountered under different soil conditions, the contactor must maintain a large inventory in order to supply sheathing and cross-braces for all trenches. Partly because of this and the relatively short life of the wood members, the contractor is constantly buying new wood members and cutting them for the anticipated sizes required for a particular job.

One of the primary objects of the present invention is to provide a universal sheathing or shoring structure which overcomes the above limitations. In designing a structure to accomplish this objective, the problem of p1acing sheathing in a trench was also considered. Most pipe or sewer line trenches require the planks to be placed at spaced intervals along each side of the trench. These are wedged in position by manually Wedging the precut cross members between each pair of planks. Various methods are used to set this type of sheathing in position, the most common requiring .a man on each side of the trench and one at the bottom to set the cross braces. This is both time consuming and costly when the number of man hours to set the sheathing is considered. It should be remembered that the trench can be dug by a trench digger at a greater speed than the men can set the sheathing. Since the amount of open trench between the last set of sheathing and trenching machine is also set by law, the speed at which a trench can be dug will depend on the men.

Another object, therefore, is to provide a universal sheathing structure which is light in weight and low in cost.

A further object is to provide an improved sheathing structure which can be set by one man and adjusted in width from the top of the trench.

A still further object of this invention is to provide an improved sheathing structure which has an unlimited life and can be quickly and easily assembled and disassembled.

Another object of this invention is to provide an improved sheathing or shoring structure which can be quickly and easily removed from the trench during back filling of the trench.

These objects are accomplished by connecting a pair of reinforced sheet metal panels to each other in a parallel relation so that the distance between them can be adjusted as desired. Each panel is made of sheet steel with the longitudinal surfaces completely smooth for easier longitudinal movement in the trench. Adjustable cross braces are provided between each pair of panels to adjust the distance between each pair of panels. Each cross brace is made up of a pair of T-members, each of which includes a tubular brace that is internally threaded. The T-membets are connected by a threaded member which has reverse threaded screws on either end. The threaded member is turned to move the T-members toward or away from each other. The cross bars forming the top of the 3,331,210 Patented July 18, 1967 T-members are secured to the panels by removable clamps which allow for pivotal motion of the cross-members so that the panels can be closed one against the other for storage or in removing the panels from the trench. Handles are provided at the top of each panel to pull the panels out of the trench. If the panels are pulled out while they are still connected by the cross-members, the one being pulled out will pivot upward against the other so that they come out as a unit.

These and other objects and advantages will become more readily apparent from the following detailed description when read in connection with the enclosed drawings in which:

FIG. 1 is a perspective View of the sheathing or shoring structures.

FIG. 2 is a side view in elevation of the sheathing and shoring structures in the full open position.

FIG. 3 is a perspective View of a cross-member used in the improved sheathing and shoring device.

Referring to the drawings in detail, and specifically to FIG. 1, the improved sheathing structure includes a pair of sheet metal panels 10, positioned in a parallel spaced relation. Cross braces 12., three being shown by way of example only, are secured to the surface of the inner section 14 of each panel by split-type U-clamps 1-6. The number of cross braces provided on each sheathing or shoring structure is dependent on the length of the panel. Handles 18 are secured to the top of each panel so that the panels can be lowered or lifted individually or as a unit, depending on whether the sheathing structure is set or taken out as a single unit or as separate panels.

The reinforced panels are made from a single strip of sheet metal which has an outer corrugated section 50 and a smooth inner section 14. The inner section is bent back on a line 52 into engagement with the corrugations and welded on line 54. Slots 40 are then cut in the panel to support the clamps as described below. The corrugations and inner sections both present a smooth longitudinal surface for easy removal of the panels from the trench. The corrugations provide .a reinforcement for the panel as is well known in the art. The panels can be cut to any desired length with twelve feet being recommended. When completed the panel will be approximately eight inches in width.

In FIG. 3, one of the cross braces is shown and includes a pair of T-members 20, with the base 22 of each T-member internally threaded to receive a threaded screw member 24 having a turning nut 26 located in the center. The T-member is made up of a one-inch pipe for the base 22 welded to the center of a one and a quarter inch pipe which form the top 24 of the Tamember. The reverse threaded screw has a right hand thread 23 at one end and a left hand thread 25 at the other end. By rotat ing the turning nut in either direction the distance between the T-members and consequently the panel members can be quickly and easily varied. The threaded screw member is designed to provide a Width variation from 20 to 35 inches.

The split U-type clamps 16 are made up of identical sections 28 having a base 30 and a connecting tab 32, the latter of which has an aperture 34 to receive a nut 36 and screw 38. The clamps are mounted on the panel by inserting the base 30 of each section into one of the slots 40 cut on the inside surface of the panel. In mounting the cross braces on the panel, two of the sections 28 are inserted into corresponding slots 40 and a nut 36 and a screw 38 tightened through aperture 34. One end of the top 24 of the T-member is then inserted in the clamp and a second set of sections 28 inserted into slots 40 and a nut 36 and screw 38 tightened through aperture 34. The distance between the clamps is less than the distance from the base of the T-mernber to the level of the top of the T-member so that it cannot come out of the clamps. The clamps are designed slightly larger than the crossbar of the T-member to allow for pivotal motion of the cross-member. A second set of clamps are (then mounted on the opposite panel for the other end of the cross member.

The sheathing structures can be stored either as a unit or as independent parts. It stored as a unit it is assembled above ground. When stored as a unit it can be used immediately, simply by lifting it by the handles and setting it into a trench. One side will contact the bottom of the trench and the other side will drop down or is pushed down to set the structure in position. The panels are wedged against the walls by merely turning the nut 26. This is a quick and very simple means of setting the sheathing. A complete unit weighs less than one hundred pounds so it can be handled quite easily by one man.

When the sheathing structure is removed from the trench, the turning nut is turned to loosen the panels. Once loosened it can be lifted out either by pulling on both handles or by pulling on one so that the panels pivot on the cross-braces to a collapsed position. Either method of removal can be accomplished by one man. When the trench is to be back filled as the sheathing is removed, the lower cross brace can be removed first by loosening the clamps. When the trench has been partly filled the second cross-brace can be removed and finally the top cross-brace. Since the outside surfaces of the panels are smooth, they will slide out of the trench with little or no difliculty.

Although only one embodiment of the present invention has been shown and described, it should be apparent that various changes and modifications can be made to the invention without departing from the scope of the appended claim.

What is claimed:

A shoring structure comprising a pair of panels positioned in a parallel relation, the

inner facing surfaces being smooth and the outer facing surfaces being corrugated,

a number of pairs of slots located at predetermined points on the inner surface of each panel,

clamp means mounted in each pair of slots,

expandable cross-brace means positioned between said panels and supported by said clamp means,

each of said clamp means includes a pair of identical, arcuate sections, having a base and a connecting tab,

said base being insertable in said slots in the panel and said tabs being interconnected to increase one end of the T-members, said cross-brace means comprising a pair of identical T-mernbers and a threaded member reverse threaded from the center outward, said T-members being interconnected by said threaded member whereby on rotation of said threaded member the T-members will be moved toward or away from each other to adjust the distance between the panels.

References Cited UNITED STATES PATENTS 841,773 1/1907 Fitzgerald 61-41 909,808 1/1909 Laughterback 6141 X 1,361,516 12/1920 Brenton 6141 X 1,649,542 11/1927 Parks 24868 2,018,920 10/1935 Mette 61-39 2,922,283 1/1960 Porter 6141 3,029,607 4/1962 Millerbernd 61-41 3,230,720 1/1966 Bennet 61-41 FOREIGN PATENTS 524,708 8/1940 Great Britain.

DAVID J. WILLIAMOWSKY, Primary Examiner.

JACOB SHAPIRO, Examiner. 

